Various systems exist for the purpose of positioning a substrate in one or more locations to allow patterns to be formed on the substrate. Some systems, such as alignment systems, attempt to position substrates by directly aligning one or more patterns on the substrates with the goal of a zero-length displacement. Moiré patterns or other particular patterns such as a box and a cross may be used for this purpose.
With existing alignment systems, the positioning of substrates may be poorly quantized and may not be useful in instances where a non-zero displacement is desired. In addition, the overlay of components of a fabrication system such a mask or a mold may not be possible. It would be desirable to be able to accurately quantize the position or positions of substrates.